Plasticization of neutralized sulfonated elastomeric polymer

Abstract

This invention relates to an improved elastomeric composition of metal and ammonium neutralized sulfonated elastomeric polymers which are preferentially plasticized with a critically selected non volatile amine at a minimum critical concentration level of at least 8 parts by weight based on 100 parts by weight of the metal neutralized elastomeric polymer, wherein the plasticized compositions have improved physical or rheological properties. These elastomeric compounds can be processed on conventional plastic fabrication equipment.

What is claimed is: 
     
       1. An elastomeric composition including: (a) a neutralized sulfonated elastomeric polymer having about 15 to 60 meq metal sulfonate groups per 100 grams of said sulfonated elastomeric polymer; and   (b) at least about 10 parts by weight of an organic amine based on 100 parts of said neutralized sulfonated elastomeric polymer, wherein said amine is selected from the group consisting of mono and di-substituted amino naphthalene compounds, amino alkyl naphthalene compounds, and saturated n-alkyl amines and mixtures thereof, wherein the alkyl groups of said n-alkylamine has at least about 20 carbon atoms.   
     
     
       2. A composition according to claim 1, wherein said neutralized sulfonated elastomeric polymer is formed from an elastomeric polymer selected from the group consisting of Butyl rubber and an EPDM terpolymer. 
     
     
       3. A composition according to claim 2, wherein said EPDM terpolymer consists essentially of about 40 to about 80 wt. % of ethylene, of about 10 to about 53 wt. % of propylene and of about 1 to about 10 wt. % of a nonconjugated diene. 
     
     
       4. A composition according to claim 3, wherein said non conjugated diene is selected from the group consisting of 1,4-hexadiene, dicyclopentadiene, alkylidene substituted norbornenes, alkenyl substituted norbornenes and tetrahydroindene. 
     
     
       5. A composition according to claim 4, wherein said non conjugated diene is 5-ethylidene-2-norbornene. 
     
     
       6. A composition according to claim 1, wherein said metal cation of said metal neutralized sulfonated polymer is selected from the group consisting of Groups I-A, II-A, I-B and II-B, lead, antimony and iron of the Periodic Table of Elements. 
     
     
       7. A composition according to claim 1, wherein said amine is 1,5-diamino naphthalene, 8-amino-2-naphthol, arachidylamine and behenylamine. 
     
     
       8. A composition according to claim 1, wherein said amine has a melting point of at least about 70° C. 
     
     
       9. A composition according to claim 1, wherein said metal cation is zinc.